Drought Adaptation Mechanisms Should Guide Experimental Design

The mechanism, or hypothesis, of how a plant might be adapted to drought should strongly influence experimental design. For instance, an experiment testing for water conservation should be distinct from a damage-tolerance evaluation. We define here four new, general mechanisms for plant adaptation to drought such that experiments can be more easily designed based upon the definitions. A series of experimental methods are suggested together with appropriate physiological measurements related to the drought adaptation mechanisms. The suggestion is made that the experimental manipulation should match the rate, length, and severity of soil water deficit (SWD) necessary to test the hypothesized type of drought adaptation mechanism.

TrendsMuch work has been done recently on improving crop water conservation through physiological assays for stomatal closure at high evaporative demand.Advances in metabolomics technology have allowed physiologists to assess plant response to water stress through new eyes.Advances in high-throughput phenotyping for physiological responses to water stress offer great promise in coupling abiotic stress tolerance with plant breeding efforts.Despite recent experimental developments, the concepts of how to define drought adaptation mechanisms and the experimental protocols for measuring these have had less attention. A new focus on the experimental methodology will be necessary to more precisely control water stress in plant biology, metabolomics, high-throughput phenotyping, and breeding experiments.